#ifndef MULTIBOOT_HEADER
#define MULTIBOOT_HEADER 1

#include <compiler.h>

// References https://www.gnu.org/software/grub/manual/multiboot/multiboot.html

#define MULTIBOOT_MAGIC 0x1BADB002
#define CHECKSUM(flags) -(MULTIBOOT_MAGIC + flags)

/* This should be in %eax. */
#define MULTIBOOT_BOOTLOADER_MAGIC              0x2BADB002

/* Alignment of multiboot modules. */
#define MULTIBOOT_MOD_ALIGN                     0x00001000

/* Alignment of the multiboot info structure. */
#define MULTIBOOT_INFO_ALIGN                    0x00000004

/* Flags set in the ’flags’ member of the multiboot header. */

/* Align all boot modules on i386 page (4KB) boundaries. */
#define MULTIBOOT_PAGE_ALIGN                    0x00000001

/* Must pass memory information to OS. */
#define MULTIBOOT_MEMORY_INFO                   0x00000002

/* Must pass video information to OS. */
#define MULTIBOOT_VIDEO_MODE                    0x00000004

/* This flag indicates the use of the address fields in the header. */
#define MULTIBOOT_AOUT_KLUDGE                   0x00010000

/* Flags to be set in the ’flags’ member of the multiboot info structure. */

/* is there basic lower/upper memory information? */
#define MULTIBOOT_INFO_MEMORY                   0x00000001
/* is there a boot device set? */
#define MULTIBOOT_INFO_BOOTDEV                  0x00000002
/* is the command-line defined? */
#define MULTIBOOT_INFO_CMDLINE                  0x00000004
/* are there modules to do something with? */
#define MULTIBOOT_INFO_MODS                     0x00000008

/* These next two are mutually exclusive */

/* is there a symbol table loaded? */
#define MULTIBOOT_INFO_AOUT_SYMS                0x00000010
/* is there an ELF section header table? */
#define MULTIBOOT_INFO_ELF_SHDR                 0X00000020

/* is there a full memory map? */
#define MULTIBOOT_INFO_MEM_MAP                  0x00000040

/* Is there drive info? */
#define MULTIBOOT_INFO_DRIVE_INFO               0x00000080

/* Is there a config table? */
#define MULTIBOOT_INFO_CONFIG_TABLE             0x00000100

/* Is there a boot loader name? */
#define MULTIBOOT_INFO_BOOT_LOADER_NAME         0x00000200

/* Is there a APM table? */
#define MULTIBOOT_INFO_APM_TABLE                0x00000400

/* Is there video information? */
#define MULTIBOOT_INFO_VBE_INFO                 0x00000800
#define MULTIBOOT_INFO_FRAMEBUFFER_INFO         0x00001000

#define present(flags, info)      ((flags) & (info))

#ifndef __ASM__

typedef unsigned char multiboot_uint8_t;
typedef unsigned char u8;
typedef unsigned short multiboot_uint16_t;
typedef unsigned short u16;
typedef unsigned int multiboot_uint32_t;
typedef unsigned int u32;
typedef unsigned long long multiboot_uint64_t;
typedef unsigned long long u64;

struct multiboot_symbol_table
{
    multiboot_uint32_t tabsize;
    multiboot_uint32_t strsize;
    multiboot_uint32_t addr;
    multiboot_uint32_t reserved;
};
typedef struct multiboot_symbol_table multiboot_symbol_table_t;

/* The section header table for ELF. */
struct multiboot_elf_section_header_table
{
    multiboot_uint32_t num;
    multiboot_uint32_t size;
    multiboot_uint32_t addr;
    multiboot_uint32_t shndx;
};
typedef struct multiboot_elf_section_header_table
  multiboot_elf_section_header_table_t;

struct multiboot_info
{
    /* Multiboot info version number */
    multiboot_uint32_t flags;

    /* Available memory from BIOS */
    multiboot_uint32_t mem_lower;
    multiboot_uint32_t mem_upper;

    /* "root" partition */
    multiboot_uint32_t boot_device;

    /* Kernel command line */
    multiboot_uint32_t cmdline;

    /* Boot-Module list */
    multiboot_uint32_t mods_count;
    multiboot_uint32_t mods_addr;

    union
    {
        multiboot_symbol_table_t aout_sym;
        multiboot_elf_section_header_table_t elf_sec;
    } u;

    /* Memory Mapping buffer */
    multiboot_uint32_t mmap_length;
    multiboot_uint32_t mmap_addr;

    /* Drive Info buffer */
    multiboot_uint32_t drives_length;
    multiboot_uint32_t drives_addr;

    /* ROM configuration table */
    multiboot_uint32_t config_table;

    /* Boot Loader Name */
    multiboot_uint32_t boot_loader_name;

    /* APM table */
    multiboot_uint32_t apm_table;

    /* Video */
    multiboot_uint32_t vbe_control_info;
    multiboot_uint32_t vbe_mode_info;
    multiboot_uint16_t vbe_mode;
    multiboot_uint16_t vbe_interface_seg;
    multiboot_uint16_t vbe_interface_off;
    multiboot_uint16_t vbe_interface_len;

    multiboot_uint64_t framebuffer_addr;
    multiboot_uint32_t framebuffer_pitch;
    multiboot_uint32_t framebuffer_width;
    multiboot_uint32_t framebuffer_height;
    multiboot_uint8_t framebuffer_bpp;
#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB 1
#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT 2
    multiboot_uint8_t framebuffer_type;
    union
    {
        struct
        {
            multiboot_uint32_t framebuffer_palette_addr;
            multiboot_uint16_t framebuffer_palette_num_colors;
        };
        struct
        {
            multiboot_uint8_t framebuffer_red_field_position;
            multiboot_uint8_t framebuffer_red_mask_size;
            multiboot_uint8_t framebuffer_green_field_position;
            multiboot_uint8_t framebuffer_green_mask_size;
            multiboot_uint8_t framebuffer_blue_field_position;
            multiboot_uint8_t framebuffer_blue_mask_size;
        };
    };
};
typedef struct multiboot_info multiboot_info_t;

struct multiboot_color
{
    multiboot_uint8_t red;
    multiboot_uint8_t green;
    multiboot_uint8_t blue;
};

struct multiboot_mmap_entry
{
    multiboot_uint32_t size;
    multiboot_uint32_t addr_low;
    multiboot_uint32_t addr_high;
    multiboot_uint32_t len_low;
    multiboot_uint32_t len_high;
#define MULTIBOOT_MEMORY_AVAILABLE 1
#define MULTIBOOT_MEMORY_RESERVED 2
#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE 3
#define MULTIBOOT_MEMORY_NVS 4
#define MULTIBOOT_MEMORY_BADRAM 5
    multiboot_uint32_t type;
} packed;

typedef struct multiboot_mmap_entry multiboot_memory_map_t;

struct multiboot_mod_list
{
    /* the memory used goes from bytes ’mod_start’ to ’mod_end-1’ inclusive */
    multiboot_uint32_t mod_start;
    multiboot_uint32_t mod_end;

    /* Module command line */
    multiboot_uint32_t cmdline;

    /* padding to take it to 16 bytes (must be zero) */
    multiboot_uint32_t pad;
};
typedef struct multiboot_mod_list multiboot_module_t;

/* APM BIOS info. */
struct multiboot_apm_info
{
    multiboot_uint16_t version;
    multiboot_uint16_t cseg;
    multiboot_uint32_t offset;
    multiboot_uint16_t cseg_16;
    multiboot_uint16_t dseg;
    multiboot_uint16_t flags;
    multiboot_uint16_t cseg_len;
    multiboot_uint16_t cseg_16_len;
    multiboot_uint16_t dseg_len;
};

#define MB_MMAP_ENTRY_SIZE      sizeof(multiboot_memory_map_t)

#endif
#endif